


The Ninth Planet

by jellybeanforest



Category: Avengers Academy (Video Game)
Genre: Alternate Universe - High School, Bucky Barnes Is a Good Bro, Bucky staunchly believes Pluto is a planet, Cap_Ironman Tiny Reverse Bang, Getting Together, M/M, Planet 9 Theories, Pluto Discourse, Pre-Slash, Rated for swearing, Steve forces him to attend a mandatory one-on-one tutoring session, Tony is a tutor, steve has a crush
Language: English
Status: Completed
Published: 2020-08-29
Updated: 2020-08-29
Packaged: 2021-03-06 21:55:32
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 1,002
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/26176075
Author URL: https://archiveofourown.org/users/jellybeanforest/pseuds/jellybeanforest
Summary: “I know you know about Planet 9.”“Of course I know about Pluto, our smallest and most delinquent planet – a friend – who doesn’t?” Bucky shrugs, being deliberately obtuse.“Not…” Steve sighs, pinches the bridge of his nose between thumb and forefinger and massages the space there, as if to stave off a headache. “We’ve been through this. Pluto isn’t a planet.”“You shut your goddamn trash mouth, Steven Grant Rogers.”For the 2020 Cap-IronMan Tiny Reverse Bang. Based on a prompt (SILVER) by Selofain.
Relationships: James "Bucky" Barnes & Steve Rogers, Steve Rogers/Tony Stark
Comments: 17
Kudos: 146
Collections: 2020 Cap/Iron Man Tiny Reverse Bang





	The Ninth Planet

**Author's Note:**

  * For [Selofain](https://archiveofourown.org/users/Selofain/gifts).
  * Inspired by [On Planet 9](https://archiveofourown.org/works/25139398) by [Selofain](https://archiveofourown.org/users/Selofain/pseuds/Selofain). 



“I can’t believe you,” Steve says as he frog-marches Bucky through the halls of Avengers Academy after class.

“What?”

“I know you know about Planet 9.”

“Of course I know about Pluto, our smallest and most delinquent planet – a friend – who doesn’t?” Bucky shrugs, being deliberately obtuse.

“Not…” Steve sighs, pinches the bridge of his nose between thumb and forefinger and massages the space there, as if to stave off a headache. “We’ve been through this. Pluto isn’t a planet.”

“You shut your goddamn trash mouth, Steven Grant Rogers.”

“Okay, but if you’re counting dwarf planets, then you have to count Ceres, and that would make Neptune the ninth planet in the solar system, but all that’s beside the point. The point is that you know about Planet 9 theories, and you still chose to write _your section of our group project on Pluto_.”

“…I stand by my decision.”

Steve throws up hands in frustration. “Alright. Fine. But did you have to drag the rest of us into your little poorly-conceived academic protest? It was a group project, Buck.”

"We didn’t fail. Mr. Fury is letting me rewrite it–”

“You’re lucky he’s letting you.”

But Bucky just rolls his eyes, hooking his thumbs in his jeans. “He was never going to fail us. Not when you’re the star quarterback–”

Steve had never been one to rest on his laurels, and so he tells Bucky, “I don’t care about that. I’m not going to coast my senior year just because I have a good arm–”

“Then do it because you already got into your dream school, and they’re not going to rescind their offer because you got an B+ in one of the lesser sciences,” Bucky says, coming to a stop outside their astronomy classroom where Mr. Fury had arranged his mandatory tutoring lesson. “Besides, I don’t see what the problem is. My argument was well-researched, my thesis on the definition of planets based on historical considerations rock solid.”

“…I should have let Sam throttle you.”

“There’s still time.”

“Don’t tempt me.” Steve places a hand on the doorknob. “I’m not bailing you out by re-writing your section either. It’s your screw-up; you’re going to take responsibility and fix it.”

“Mm hm,” Bucky hums, barely paying attention.

Steve frowns. “I mean it, Bucky. I’m just here to make sure you attend this make-up session, and then I’m out. You’re on your own.”

“I heard you the first time.”

“And I don’t think you believe me, but I’m being serious.” He opens the door, to find the lone occupant at the chalkboard, erasing his prior lesson.

Steve is struck speechless, suddenly shy in the presence of resident genius and his long-time crush: Tony Stark.

“…Did I mention that Tony Stark himself is going to be leading this little lesson? One-on-one tutoring. For an hour, Steve. A little tete-a-tete with whoever needs help understanding theories about Planet 9,” Bucky, that smug asshole, mutters low so only Steve can hear before repeating “For an hour” for emphasis, as if the guy didn’t hear him the first time.

Steve turns to his friend-slash-traitor, his eyes wide as he whispers, “You did this on purpose.”

“Which one of you is here for the makeup lesson?” Tony inquires, chalk poised in hand.

Steve sits down before he manages to trip over his own feet.

“I’ll just…” Bucky edges towards the door, “leave you to it. He needs a lot of help, you know. A lot of special attention.”

“I can help you pass, if you’re willing to put in the work.” Tony addresses Steve, clearly unimpressed with his assumed-to-be-low intellectual aptitude. It’s not that Steve blames him. He’s always in knots around the guy, never knowing what to say, his mind blanking whenever he happened to be within earshot of the handsome brunette.

Bucky speaks on his behalf. “Oh, it might take a while. Maybe you two can get burgers later.”

Steve turns in his chair. “Bucky,” he hisses in warning.

Tony only squints, his brow furrowed in confusion. “Are– are you asking me out on Steve’s behalf?”

Steve blushes.

“Depends. Is it working?” Bucky asks, gracing him with a roguish grin.

Steve throws a pencil at his head. Despite his proximity to Tony, he has impeccable aim, hitting Bucky square on the forehead with the eraser end.

Tony only thins his eyes at the display. “This is a bit,” he says slowly. “You’re doing a bit. What happened? Steve lose a bet?”

“No!” Steve says, his voice much too high. He clears his throat and wipes his sweaty palms on his jeans before continuing, “No… I mean… if– if you want, I’m free after… but only if you want.”

Tony gives him a once-over. It’s obvious the possibility that the quarterback of all people might be into him had never even crossed his mind. “…Okay,” he agrees, “but only if you can tell me how the unusual clustering of extreme trans-Neptunian objects relates to Planet 9–”

“Gravitational pull!” Steve spouts off quickly and a touch too loud. He ignores Bucky’s snigger behind him. “There might be a super-sized earth in the outer solar system pulling them into a weird tilted elliptical orbit around the sun.”

Tony only blinks, dumbfounded that the student he assumed to be just another dumb jock actually knew the answer right off the bat, before they could even review the material. “I meant after the lesson,” he clarifies.

Steve’s head drops down, lightly thumping the desk. “…Of course.”

“I’ll leave you two to it,” Bucky says, already halfway out the door. “Call me later, Stevie. Have fun. I won’t wait up. I’ve got a paper to write anyway.”

The door shuts, leaving Steve and Tony together. Alone.

“He always like that?” Tony asks Steve.

“Constantly.”

“Huh. With friends like that…”

“Yep.”

Tony cants his head in consideration. “Would you really like to get burgers later?” he asks.

Steve blinks. “Yes, I’d like that.”

“Me too.” Tony turns to the board. “Now about Planet 9…”

**Author's Note:**

> Basically, outside Neptune, there are a bunch of objects (eTNOs) that orbit the sun at a similar tilt, all making their closet approaches to the sun in the same sector. This improbable alignment suggests that there might be a Planet 9 with a mass of 5-10 Earths travelling in an elongated orbit in the outer solar system 400-800 times the distance between the sun and earth. The gravity of this outer planet might be what causes the clustering of these eTNOs.
> 
> There are currently five dwarf planets identified in our solar system: Ceres which lies between Mars and Jupiter, Pluto, then Haumea, Makemake, and Eris beyond Pluto. Eris is the largest of the dwarf planets, and its discovery in 2003 prompted a re-evaluation of Pluto's status as the ninth planet in the solar system.


End file.
